^noobie mistake... :-|
never compress the brakes on hydro's. since they're hydraulic, the oil that is forcing the pads together is now holding them together, i never found a website why, but i just know that when you compress them fully, they end up not comming back to home. i'm not really sure what to do but i know that once i partially pressed them on accident, but was still able to get the rotor in. so i slipped my rotor in, and then just pumped the pads a few times, that caused it to go back to normal.
either, there is a way you can stick a screwdriver or something in to the caliper body to contract the pads, or you're gonna have to buy new pads and put them on.